1. Field
Quantum dots and devices including the same are disclosed.
2. Description of the Related Art
Nanoparticles have physical characteristics (e.g., energy bandgaps and melting points) that depend on particle size, unlike bulk materials. For example, a semiconductor nanocrystal, also known as a quantum dot (QD) is a semiconductor material having a crystalline structure with a size of several nanometers. Quantum dots have such a small size that they have a large surface area per unit volume and exhibit quantum confinement effects, and thus have different physicochemical characteristics from the characteristics of the bulk material. Quantum dots may absorb light from an excitation source and may emit light energy corresponding to an energy bandgap of the quantum dot. In the quantum dots, the energy bandgap may be selected by controlling the sizes and/or the compositions of the nanocrystals. Also, QDs have desirable photoluminescence properties and have a high color purity. Therefore, QD technology is used for various applications, including a display device, an energy device, a bio-light emitting element, or the like.
A quantum dot having a core-shell structure may have a slightly increased luminous efficiency due to surface passivation by the shell, however most of these systems include cadmium. Cadmium poses serious environmental problems, and thus it is desirable to provide a cadmium-free semiconductor nanocrystal particle with desirable light emitting properties.
Electronic devices including quantum dots may be operated in a high temperature environment; and thereby luminous efficiency of the quantum dots may be adversely affected by the ambient temperature. Therefore, there is a need to develop quantum dots in which the negative impact of temperature is reduced.